91分蒟蒻求救
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91分蒟蒻求救
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绊城烟雨“grz楼主2021/2/4 20:43
#include<bits/stdc++.h>
using namespace std;
const int MAXN=8e6+10;
int n,m,cnt;
int head[MAXN],vis[MAXN];
long long dist[MAXN];
int mapp[2001][2001];
int ans[MAXN];
struct node{
	int nxt,to,w;
}e[MAXN];
struct point{
	int id;
	long long dis;
	friend bool operator < (point a,point b){
		return a.dis>b.dis;
	}
};
void add(int x,int y,int z){
	e[++cnt].nxt=head[x];
	e[cnt].to=y;
	e[cnt].w=z;
	head[x]=cnt;
}
priority_queue<point>q;
void dij(){
	ans[1]=1;
	memset(dist,0x3f,sizeof(dist));
	dist[1]=0;
	q.push({1,0});
	while(!q.empty()){
		int tmp=q.top().id;
		q.pop();
		if(vis[tmp])
			continue;
		vis[tmp]=1;
		for(int i=head[tmp];i;i=e[i].nxt){
			int v=e[i].to;
			int w=e[i].w;
			if(dist[v]>dist[tmp]+w){
				dist[v]=dist[tmp]+w;
				q.push({v,dist[v]});
				ans[v]=ans[tmp];
			}
			else if(dist[v]==dist[tmp]+w)
				ans[v]+=ans[tmp];
		}
	}
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		int x,y,z;
		cin>>x>>y>>z;
		if(mapp[x][y]==0){
			add(x,y,z);
			mapp[x][y]=1;
		}
		else
			continue;
	}
	dij();
	if(dist[n]>9999999999)
		cout<<"No answer";
	else
		cout<<dist[n]<<" "<<ans[n];
	return 0;
}

萌新怀疑是不是要特判,求各位大佬指出

2021/2/4 20:43
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